"God only knows how much I wish that bullet would have hit me," said Joanne Sanabria, calling her little boy "my angel."
Police said the suspected shooter, Nicholas Morris, 26, surrendered Monday night after calling them from the office of a city cable television station, where he gave an interview proclaiming his innocence.
"I did not shoot anybody ever in my life," Morris said in the interview.
Charges against him are pending. Authorities are searching for another Bronx man, Ronneil Gilliam, 25, who they said was with Morris during the shooting.
Sanabria said she wanted her son's killer to remember him.
"I want him to wake up every day and see my face and hear my voice and see my son's picture every day," she told reporters hours before Morris turned himself in.
David Pacheco Jr., dressed in his Easter best, was strapped in a car seat Sunday afternoon as the family drove through the Bronx a few miles from home.
"I was driving and I heard the gunshot and I heard my son screaming," Sanabria, 28, said Monday.
Her daughters, ages 8 and 11, and her sister's family were also in the vehicle but unharmed.
Investigators believe the tragedy stemmed from a confrontation between two groups of men. At one point, Morris or Gilliam slapped another man. When the man's friends intervened, the pair retreated to an apartment, grabbed a gun and opened fire at the group from across the street just as the van was passing by, police said.
An off-duty emergency medical technician, Angelo Cruz, heard the gunfire and ran to help the toddler, but the shooter disappeared. The little boy had been struck in the chest and was pronounced dead about 45 minutes later.
His father, David Pacheco, said Monday he owes his thanks to Cruz. He said the resuscitation effort gave him time to see his son alive one last time.
Grieving family and friends described the boy as energetic and always smiling. "He was a happy kid," his uncle Victor Castillo said.